"""
大文件上传和处理API端点
支持分片上传、断点续传、文件处理
"""
import json
from typing import Dict, List, Optional, Any
from fastapi import APIRouter, Depends, HTTPException, status, UploadFile, File, Form, Body
from fastapi.responses import StreamingResponse
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.deps import get_current_active_user, get_db
from app.models.user import User
from app.services.file_upload_service import file_upload_service, file_processor
from app.core.logging import get_logger

logger = get_logger(__name__)

router = APIRouter()


@router.post("/upload", response_model=Dict[str, Any])
async def upload_file(
    file: UploadFile = File(...),
    custom_name: Optional[str] = Form(None),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """上传单个文件"""
    try:
        result = await file_upload_service.save_file(file, current_user.id, custom_name)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"File upload failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"File upload failed: {str(e)}"
        )


@router.post("/chunked/init", response_model=Dict[str, Any])
async def init_chunked_upload(
    filename: str = Form(...),
    total_size: int = Form(...),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """初始化分片上传"""
    try:
        result = await file_upload_service.chunked_upload_init(filename, total_size, current_user.id)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Chunked upload init failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Chunked upload init failed: {str(e)}"
        )


@router.post("/chunked/upload/{upload_id}/{chunk_number}", response_model=Dict[str, Any])
async def upload_chunk(
    upload_id: str,
    chunk_number: int,
    chunk_data: bytes = File(...),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """上传文件分片"""
    try:
        result = await file_upload_service.upload_chunk(upload_id, chunk_number, chunk_data, current_user.id)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Chunk upload failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Chunk upload failed: {str(e)}"
        )


@router.post("/chunked/complete/{upload_id}", response_model=Dict[str, Any])
async def complete_chunked_upload(
    upload_id: str,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """完成分片上传并合并文件"""
    try:
        result = await file_upload_service.complete_chunked_upload(upload_id, current_user.id)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Chunked upload completion failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Chunked upload completion failed: {str(e)}"
        )


@router.get("/chunked/status/{upload_id}", response_model=Dict[str, Any])
async def get_upload_status(
    upload_id: str,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """获取上传状态"""
    try:
        result = await file_upload_service.get_upload_status(upload_id, current_user.id)
        
        if result.get("status") == "not_found":
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Upload session not found"
            )
        elif result.get("status") == "unauthorized":
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="Unauthorized access to upload session"
            )
        elif result.get("status") == "error":
            raise HTTPException(
                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                detail=result.get("error", "Unknown error")
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Get upload status failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Get upload status failed: {str(e)}"
        )


@router.post("/process/image", response_model=Dict[str, Any])
async def process_image(
    file_path: str = Form(...),
    operations: List[str] = Form(...),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """处理图片文件"""
    try:
        result = await file_processor.process_image(file_path, operations)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Image processing failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Image processing failed: {str(e)}"
        )


@router.post("/process/text", response_model=Dict[str, Any])
async def process_text_file(
    file_path: str = Form(...),
    operations: List[str] = Form(...),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """处理文本文件"""
    try:
        result = await file_processor.process_text_file(file_path, operations)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Text file processing failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Text file processing failed: {str(e)}"
        )


@router.post("/process/pdf", response_model=Dict[str, Any])
async def process_pdf_file(
    file_path: str = Form(...),
    operations: List[str] = Form(...),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """处理PDF文件"""
    try:
        result = await file_processor.process_pdf_file(file_path, operations)
        
        if not result["success"]:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=result["error"]
            )
        
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"PDF processing failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"PDF processing failed: {str(e)}"
        )


@router.get("/files", response_model=List[Dict[str, Any]])
async def list_user_files(
    skip: int = 0,
    limit: int = 100,
    file_type: Optional[str] = None,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """获取用户上传的文件列表"""
    try:
        # 在实际实现中，这里应该从数据库查询用户文件
        # 目前返回示例数据
        
        files = [
            {
                "id": 1,
                "filename": "example.jpg",
                "file_path": "/uploads/user_1_example.jpg",
                "file_size": 1024000,
                "file_type": "image",
                "uploaded_at": "2024-01-01T12:00:00",
                "status": "completed"
            }
        ]
        
        return files
        
    except Exception as e:
        logger.error(f"Failed to list user files: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to list files: {str(e)}"
        )


@router.delete("/files/{file_id}", response_model=Dict[str, Any])
async def delete_file(
    file_id: int,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """删除用户文件"""
    try:
        # 在实际实现中，这里应该删除文件并更新数据库
        # 目前返回成功消息
        
        return {
            "success": True,
            "file_id": file_id,
            "message": "File deleted successfully"
        }
        
    except Exception as e:
        logger.error(f"Failed to delete file {file_id}: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to delete file: {str(e)}"
        )


@router.get("/download/{file_id}")
async def download_file(
    file_id: int,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """下载文件"""
    try:
        # 在实际实现中，这里应该根据file_id查找文件并返回文件流
        # 目前返回示例响应
        
        # 示例文件内容
        content = "This is a sample file content"
        
        return StreamingResponse(
            iter([content]),
            media_type="application/octet-stream",
            headers={"Content-Disposition": f"attachment; filename=file_{file_id}.txt"}
        )
        
    except Exception as e:
        logger.error(f"Failed to download file {file_id}: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to download file: {str(e)}"
        )


@router.get("/stats", response_model=Dict[str, Any])
async def get_file_stats(
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """获取文件上传统计信息"""
    try:
        # 在实际实现中，这里应该从数据库统计用户文件信息
        # 目前返回示例数据
        
        stats = {
            "total_files": 10,
            "total_size": 102400000,  # 100MB
            "file_types": {
                "image": 5,
                "pdf": 2,
                "text": 3
            },
            "last_upload": "2024-01-01T12:00:00"
        }
        
        return stats
        
    except Exception as e:
        logger.error(f"Failed to get file stats: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to get stats: {str(e)}"
        )